title: Calibrating and controlling the quantum efficiency distribution of inhomogeneously broadened quantum rods by using a mirror ball.
abstract: We demonstrate that a simple silver coated ball lens can be used to accurately measure the entire distribution of radiative transition rates of quantum dot nanocrystals. This simple and cost-effective implementation of Drexhage's method that uses nanometer-controlled optical mode density variations near a mirror, not only allows an extraction of calibrated ensemble-averaged rates, but for the first time also to quantify the full inhomogeneous dispersion of radiative and non radiative decay rates across thousands of nanocrystals. We apply the technique to novel ultrastable CdSe/CdS dot-in-rod emitters. The emitters are of large current interest due to their improved stability and reduced blinking. We retrieve a room-temperature ensemble average quantum efficiency of 0.87 ± 0.08 at a mean lifetime around 20 ns. We confirm a log-normal distribution of decay rates as often assumed in literature, and we show that the rate distribution-width, that amounts to about 30% of the mean decay rate, is strongly dependent on the local density of optical states.
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands. plha@fotonik.dtu.dk
authors.forename: Per
authors.initials: P
authors.lastname: Lunnemann
authors.forename: Freddy T
authors.initials: FT
authors.lastname: Rabouw
authors.forename: Relinde J A
authors.initials: RJ
authors.lastname: van Dijk-Moes
authors.forename: Francesca
authors.initials: F
authors.lastname: Pietra
authors.forename: Daniël
authors.initials: D
authors.lastname: Vanmaekelbergh
authors.forename: A Femius
authors.initials: AF
authors.lastname: Koenderink
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D045663:Quantum Dots; D011789:Quantum Theory; D018036:Selenium Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; C034939:cadmium sulfide; C058667:cadmium selenide